Self-Assembled Tannic Acid Complexes for pH-Responsive Delivery of Antibiotics: Role of Drug-Carrier Interactions

Publication date: Available online 7 March 2019Source: International Journal of PharmaceuticsAuthor(s): Sara A. Abouelmagd, Noura H. Abd Ellah, Omar Amen, Alshaimaa Abdelmoez, Noha G. MohamedAbstractSelf-assembled particles, based on non-covalent interactions, are attractive drug carriers with a relatively simple structure and easy preparation. Tannic acid (TA) is an anionic polyphenolic compound with a wide range of molecular interactions and diverse applications in drug delivery research. Here, we propose the use of TA complexes with cationic antibiotics as a new pH-responsive drug carriers of high drug loading and optimal stability. TA complexes were prepared with three water-soluble antibiotics; colistin sulfate (COL), gentamicin sulfate (GEN) and gatifloxacin (GAT). Complexes’ size ranged from several-hundred nanometers to few microns. For selected particles, drug loading ranged from 30-36%. Importantly, we demonstrate the impact of drug-carrier interactions, studied via infrared spectroscopy and molecular modeling, on final complex stability and performance; the complexes resisted dissociation in presence of serum at physiological pH to variable degrees and showed different drug release profiles. However, all complexes dissociated upon medium acidification, releasing their drug payload and demonstrating expected antibacterial effect. These results demonstrate that TA/antibiotic self-assembled complexes represent an excellent carrier for pH-sensitive delivery of water-...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research